While not limited thereto, the present invention is particularly adapted for use with space vehicles, used for various planetary and earth-orbital missions, which are powered by solar electric propulsion (i.e., ion drive). The solar array for such vehicles must be capable of maximum energy conversion efficiency to deliver adequate energy to power the ion thrusters at distances as great as 4.5 AU where the sun's intensity is only 1/20th of that which impinges on the earth. At the same time, a feasible solar array of this type must be lightweight, a realistic target being about 800 kilograms. Adding additional solar cell area to existing arrays is not practical since the weight increase is excessive.
In the past, various arrangements of lightweight plastic film for reflecting concentrators have been tried. These include flat side reflectors, in-panel vee-ridged concentrators, combinations of the above two arrangements, and curved parabolic side concentrators. These systems, however, are unsatisfactory since the weight of the assembly becomes excessive when the geometric concentration ratio is increased to the minimum acceptable value of 4 to 1. Furthermore, in each of the aforementioned prior art arrangements, a reflector-to-sun angle of 30.degree. or less is necessary to reflect sun rays onto the solar cells. As a result, the true reflector width is at least twice the effective width, which is an inefficient use of the reflector weight.